KR102456183B1 - Organic light emitting display device and fabricating method thereof - Google Patents

Abstract

The present invention relates to an organic light emitting display device and a method of manufacturing the same. In one aspect, the present invention relates to a first electrode positioned in each pixel region, and a first electrode on a substrate in which a plurality of pixel regions are defined. Provided is an organic light emitting display device in which auxiliary wiring is positioned on a bank defining a pixel region in a structure in which an organic light emitting layer and a second electrode are positioned to be connected to the second electrode.

Description

Organic light emitting display device and method of manufacturing the same

The present invention relates to an organic light emitting display device including auxiliary wiring and a method for manufacturing the same.

As the information society develops, the demand for a display device for displaying an image is increasing in various forms. Recently, a liquid crystal display (LCD), a plasma display panel (PDP), and an organic light emitting diode Various display devices such as a display device (OLED: Organic Light Emitting Display Device, or organic light emitting display device) are being used. Such various display devices include a display panel suitable therefor.

In the display panel, thin film transistors are formed in each pixel region, and a specific pixel region in the display panel is controlled through the flow of current in the thin film transistor. A thin film transistor consists of a gate and source/drain electrodes.

In the organic light emitting display device, a light emitting layer is formed between two different electrodes, and when electrons generated from one electrode and holes generated from the other electrode are injected into the light emitting layer, the injected electrons and holes are combined to form an exciton. ) is generated, and the generated axitons fall from an excited state to a ground state and emit light to display an image.

On the other hand, in the case of an electrode, for example, a cathode, which injects electrons in an organic light emitting display device, a voltage drop may occur due to the specific resistance of the cathode, which may increase as the size of the display device increases. leads to a decline Therefore, it is necessary to form an auxiliary wiring (or auxiliary electrode) to solve the voltage drop. In addition, it is necessary to reduce the cost due to the additional process by excluding the additional mask from the configuration of the auxiliary wiring.

Against this background, an object of the present invention is to improve the uniformity of luminance of a large area organic light emitting display panel.

In addition, an object of the present invention is to reduce the voltage drop of the cathode even when it is formed thin in order to increase the transmittance of the cathode in a top emission structure.

Another object of the present invention is to provide an auxiliary electrode and auxiliary wiring for maintaining the voltage of the cathode, and to reduce the process cost by minimizing the process of forming the auxiliary electrode and auxiliary wiring.

In order to achieve the above object, in one aspect, the present invention provides a first electrode positioned in each pixel region on a substrate in which a plurality of pixel regions are defined, and an organic light emitting layer and a second electrode positioned on the first electrode To provide an organic light emitting display device connected to a second electrode by an auxiliary wiring positioned on a bank defining a pixel region in the structure of the present invention.

In another aspect, the present invention provides an organic light emitting display device in which auxiliary wiring to which power of the same potential as that of the second electrode is applied is formed on a bank.

In another aspect, the present invention provides a method of forming a first electrode in a plurality of pixel regions on a substrate, forming a bank defining the pixel region, and then forming an auxiliary wiring on the bank to electrically connect the second electrode. A method of manufacturing an organic light emitting display device is provided.

As described above, according to the present invention, since the auxiliary wiring is located in the peripheral area of the pixel area and is connected to an electrode such as a cathode, the luminance of the display device or the entire display panel can be uniformly maintained.

Also, according to the present invention, since the auxiliary wiring may be positioned in one or more of the horizontal and vertical directions of the display panel, the resistance of the electrode such as the cathode may be reduced.

In addition, according to the present invention, since the auxiliary wiring is formed on the bank, it is possible to increase the device lifetime of the organic light emitting layer by solving the conventional problem of decreasing the aperture ratio.

1 is a diagram schematically illustrating a display device according to example embodiments.
2 is a diagram showing a structure in which a voltage drop occurs.
3 is a graph showing a decrease in luminance due to a voltage drop in the absence of an auxiliary electrode.
4 is a view showing a configuration of forming an auxiliary electrode with a barrier rib.
5 is a view showing a cross-section of a configuration in which auxiliary wiring is disposed according to an embodiment of the present invention.
6 is a view showing a cross-section of a configuration in which auxiliary wiring is disposed according to another embodiment of the present invention.
7 is a view comparing the opening ratio of the barrier rib structure and the structure to which the embodiment of the present invention is applied.
8 to 12 are views illustrating a process of laminating the structure of FIG. 5 according to an embodiment of the present invention.
13 to 15 are plan views illustrating a process in which auxiliary wirings are stacked in the same structure as in FIG. 6 .
16 is a view showing auxiliary wiring arranged on a bank in a panel when the present invention is applied.
17 is an embodiment in which auxiliary wirings are formed only in a part of non-opening areas between pixel areas.
18 is a view comparing the aperture ratio due to the arrangement of auxiliary wirings and the aperture ratio due to the arrangement of auxiliary wirings in the partition structure of FIG. 4 .
19 is a view showing an increase in the luminance lifetime of a panel according to an increase in the aperture ratio due to the application of the present invention.
20 is a view showing a process of manufacturing an organic light emitting display device according to an embodiment of the present invention.
21 is a view showing a cross-section in which the photoresist on the auxiliary wiring is removed according to an embodiment of the present invention.
22A and 22B are views illustrating a cross-section of an auxiliary wiring according to another embodiment of the present invention in a double layer.

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. In adding reference numerals to components of each drawing, the same components may have the same reference numerals as much as possible even though they are indicated in different drawings. In addition, in describing the present invention, when it is determined that a detailed description of a related known configuration or function may obscure the gist of the present invention, the detailed description may be omitted.

In addition, in describing the components of the present invention, terms such as first, second, A, B, (a), (b), etc. may be used. These terms are only for distinguishing the elements from other elements, and the essence, order, order, or number of the elements are not limited by the terms. When it is described that a component is “connected”, “coupled” or “connected” to another component, the component may be directly connected or connected to the other component, but other components may be interposed between each component. It should be understood that each component may be “interposed” or “connected,” “coupled,” or “connected” through another component.

1 is a diagram schematically illustrating a display device according to example embodiments.

Referring to FIG. 1 , in the display device 100 according to the embodiments, a plurality of first lines VL1 to VLm are formed in a first direction (eg, a vertical direction), and a second direction (eg, a horizontal direction) is formed. ), a display panel 110 having a plurality of second lines HL1 to HLn formed therein, a first driver 120 supplying a first signal to a plurality of first lines VL1 to VLm, and a plurality of first lines. It includes a second driver 130 for supplying a second signal to the two lines HL1 to HLn, and a timing controller 140 for controlling the first driver 120 and the second driver 130 .

The display panel 110 includes a plurality of first lines VL1 to VLm formed in a first direction (eg, a vertical direction) and a plurality of second lines HL1 to HLn formed in a second direction (eg, a horizontal direction). A plurality of pixels (P: Pixel) are defined according to the intersection of .

Each of the first and second drivers 120 and 130 described above may include at least one driver IC that outputs a signal for displaying an image.

The plurality of first lines VL1 to VLm formed in the first direction on the display panel 110, for example, are formed in a vertical direction (first direction) to transmit data voltages (first signals) to pixel columns in the vertical direction. may be a data line, and the first driver 120 may be a data driver that supplies a data voltage to the data line.

In addition, the plurality of second lines HL1 to HLn formed in the second direction on the display panel 110 are formed in the horizontal direction (second direction) to transmit the scan signal (first signal) to the pixel column in the horizontal direction. It may be a wire, and the second driver 130 may be a gate driver that supplies a scan signal to the gate wire.

In addition, a pad part is configured in the display panel 110 to connect to the first driving part 120 and the second driving part 130 . When a first signal is supplied from the first driver 120 to the plurality of first lines VL1 to VLm, the pad unit transmits it to the display panel 110 , and similarly, the second driver 130 provides a plurality of second lines ( When the second signal is supplied to HL1 to HLn), it is transmitted to the display panel 110 .

Each pixel includes one or more subpixels. The sub-pixel refers to a unit in which a specific color filter is formed or a color filter is not formed and the organic light emitting device can emit a special color. The colors defined in the sub-pixel may include red (R), green (G), blue (B), and optionally white (W), but the present invention is not limited thereto. Since each subpixel includes a separate thin film transistor and an electrode connected thereto, the subpixel constituting the pixel is also referred to as one pixel area hereinafter.

On the other hand, organic light emitting display devices include top emission, bottom emission, and dual emission. In a large-area display panel where the display panel increases regardless of which light emitting method is selected, a voltage drop of the cathode may occur in the process of forming the cathode on the front surface. can Hereinafter, although a top-emitting display device will be mainly described in this specification, embodiments of the present invention are not limited to top-emitting display devices, and may be applied to any structure of a display device that prevents a voltage drop of a cathode.

2 is a diagram showing a structure in which a voltage drop occurs. Looking at the structure in which power is applied from the display panel, the power supply unit 190 provides the base power such as 180a or 180b through the first driving unit 120 or the second driving unit 130 to the display area 111 of the display panel. is authorized Since the base power is applied at the upper and lower edges, the luminance is highest in the edge region of the display region 111 and the luminance is lowest in the center of the panel. These features will be described in detail in FIG. 3 .

3 is a graph showing a decrease in luminance due to a voltage drop in the absence of an auxiliary electrode. Referring to FIG. 3 , as shown in 180a and 180b of FIG. 2 , the luminance is high in the edge region to which the base power is supplied, and the luminance is low in the center region. This phenomenon occurs more significantly when the size of the display device is increased. Accordingly, an auxiliary electrode is required to prevent voltage enhancement and luminance deterioration due to the voltage increase.

In an organic light emitting display device, which is a conventional top light emitting device, a luminance non-uniformity may occur due to a high resistance of the cathode by using a thin-film cathode (~100 Å). In addition, there is a limitation in applying the auxiliary electrode or auxiliary wiring while depositing white EL on the entire surface of the array of the panel. As an embodiment to solve this problem, there is a method of improving the uniformity of luminance by introducing a barrier rib structure and contacting the cathode and the auxiliary electrode through IZO deposition in a structure in which the auxiliary electrode is exposed even when white EL is deposited in the panel array.

4 is a view showing a configuration of forming an auxiliary electrode with a barrier rib. A buffer 402 is positioned on a substrate 401 , and an active 405 , a gate insulator 407 , a gate 410 , an interlayer dialect 415 , and a source and drain 420 are disposed on the buffer. ), a passivation layer (Passivation Layer, 425), a first planarization layer (Pacification layer, 427), and the connection electrode 430 connected to the source or drain 420, the first auxiliary composed of the same material as the connection electrode 430 The source or drain 420 and the active 405 are connected through the electrode 431 , the first electrode, or the contact hole 418 formed in the anode 440 and the interlayer insulating layer 415 in an embodiment. And a second auxiliary electrode 441 made of the same material as the anode 440 , and a bank 450 , an organic light emitting layer 470 , a second electrode or a cathode (Cathode, 480 ), and a barrier rib 490 in one embodiment. this is located

When the barrier rib structure is applied as shown in FIG. 4 , the uniformity of luminance is improved, but three layers are added to form the auxiliary electrode and the barrier rib. That is, a thick auxiliary electrode is used to reduce resistance by being connected to the cathode, and a planarization layer is added to planarize the auxiliary electrode. In addition, an undeposited region of white EL, which is deposited over the entire surface, is formed to form a structure for contacting the auxiliary electrode and the cathode.

As shown in FIG. 4, three layers are required to implement the auxiliary electrode according to the barrier rib structure, and for this purpose, an auxiliary electrode (deposition → exposure → shape → etching), a planarization layer (coating → exposure → development → heat treatment), and a barrier rib (coating) →exposure →development →heat treatment) is added. That is, since the addition of PAC is required after the TFT process, six masks are required, and a problem of lowering the aperture ratio occurs due to the auxiliary electrode contact portion. The process to which the six masks are applied is the formation of the PAC 427 , the auxiliary electrodes 430 and 431 , the PAC 435 , the anode 440 , the bank 450 , and the partition wall 490 .

In FIG. 4 , when the size of the region BO in which the bank is open to contact the auxiliary electrode 441 and the cathode 480 increases, the aperture ratio decreases.

Accordingly, in the present specification, a configuration in which auxiliary electrodes, ie, auxiliary wirings, is disposed without a decrease in the aperture ratio is proposed. To this end, embodiments of the present invention suggest a configuration in which the auxiliary wiring is located in a part or all of the area on the bank. In addition, in one embodiment of the present invention, the auxiliary wiring is applied with power having the same potential as that of the power applied to the cathode, so that the cathode is uniformly supplied to the display panel. can

Hereinafter, a buffer layer, a planarization layer (or a planarization film), a passivation layer, etc. may be referred to differently, but these are collectively referred to as a protective layer. The protective layer is a layer positioned between materials such as a source/drain and a gate, or a gate and an active layer, or an anode and a source/drain, an anode and a cathode for light emission of an OLED, and may be an organic material or an inorganic material. , the protective layer in the present invention is not limited to a specific material.

Hereinafter, the present invention will look at a configuration in which auxiliary wiring is disposed on a bank and the auxiliary wiring is connected to the second electrode, for example, the cathode electrode. When the present invention is applied in more detail, in a substrate in which a plurality of pixel regions are defined, a first electrode positioned in each pixel region, a bank defining a pixel region, auxiliary wiring on the bank, and an organic light emitting layer on the first electrode A second electrode is positioned on the upper surface, and the second electrode is electrically connected to the above-described auxiliary wiring. Since the auxiliary wiring is arranged on the bank, there is no decrease in the aperture ratio even compared to the case where the auxiliary wiring is not arranged. In addition, since auxiliary wirings can be disposed on the front surface of the panel, a change in luminance occurring in the above-described large-area display device does not occur, so that even luminance can be realized in a large-area display device.

5 is a view showing a cross-section of a configuration in which auxiliary wiring is disposed according to an embodiment of the present invention. 5 shows a case in which the connection electrode 430 is disposed between the anode 440 and the source/drain 420 .

In FIG. 5 , auxiliary wires 510a , 510b , and 510c are disposed on the bank 450 . The auxiliary wirings 510a, 510b, and 510c disposed on the bank surrounding the adjacent subpixels are electrically connected to the cathode 480 . Photoresists 515a, 515b, and 515c for forming the auxiliary wirings 510a, 510b, and 510c are disposed on the auxiliary wirings 510a, 510b, and 510c, and then on the photoresists 515a, 515b, and 515c. An organic light emitting layer 470 and a cathode 480 are deposited thereon to have a structure as shown in FIG. 5 .

6 is a view showing a cross-section of a configuration in which auxiliary wiring is disposed according to another embodiment of the present invention. 6 shows a case in which the anode 440 and the source/drain 420 are directly connected. As in FIG. 5 , auxiliary wirings 510a and 510b disposed on the bank surrounding two adjacent subpixels are electrically connected to the cathode 480 . Photoresists 515a, 515b, and 515c for forming the auxiliary wirings 510a, 510b, and 510c are disposed on the auxiliary wirings 510a, 510b, and 510c, and then organically formed on the photoresists 515a, 515b, and 515c. The light emitting layer 470 and the cathode 480 are deposited to have a structure as shown in FIG. 6 .

5 and 6 , an embodiment of the active 405 is an oxide semiconductor or low temperature poly-silicon (LTPS). The source/drain 420 , the gate 410 , and the connection electrode 430 are made of a conductive material, and may be Cu/MoTi, or a Mo/Al/Mo alloy in an embodiment, but is not limited thereto, and various materials may be applied. . The anode/reflector 440 and the auxiliary wiring 510 may use ITO or ITO/Ag/ITO. Alternatively, Cu, Mo, or an alloy thereof may be used. The bank 450 may use an overcoat (OC), and the cathode 480 as the second electrode may use ITO, IGZO, IZO, Mg, Ag, or an alloy thereof.

5 and 6 , the photoresists 515a , 515b , and 515c disposed on the auxiliary wirings 510a , 510b , and 510c may be removed.

5 and 6, the auxiliary wirings 510a, 510b, and 510c are in electrical contact with the cathode 480, which is the second electrode, at a surface forming a constant inclination angle (not less than 0 degrees and not more than 180 degrees) on the contact surface in contact with the bank. Reference numerals 590a and 590b of FIG. 5 indicate portions in which the second electrode and the auxiliary wiring are in electrical contact. Since the material constituting the second electrode has a high step-coverage, when the inclination angle of 590, which is a contact portion between the auxiliary wiring and the second electrode of FIG. 5, moves away from the right angle, the contact between the second electrode and the auxiliary wiring area can be increased. 5, 590a and 590b show the case where the inclination angle Θ between the contact surface in contact with the bank and the surface in contact with the second electrode is an acute angle and an obtuse angle, respectively.

Meanwhile, in order to increase the inclination angle, the auxiliary wiring material may be formed into a double layer. That is, when two materials having different etching degrees are configured as a double or multi-layered auxiliary wiring material, the side surface of the auxiliary wiring is inclined or curved, and as a result, the contact area between the second electrode and the auxiliary wiring. can be expanded This shape is confirmed in FIGS. 22A and 22B.

Unlike FIG. 4 in which a part of the bank is opened and the partition wall is positioned, in FIGS. 5 and 6 only the bank exists between the openings, and auxiliary wiring is disposed on the bank, so that the area of the non-opening part is reduced. The structure in which the partition wall is formed as shown in FIG. 4 and the aperture ratio when the present invention is applied are shown in FIG. 7 .

Reference numeral 710 of FIG. 7 is a plan view of the barrier rib structure of FIG. 4 . 720 is a plan view of a structure in which auxiliary wiring is formed on the bank as shown in FIGS. 5 and 6 . Comparing the non-opening area BK1 in which the partition wall 490 is disposed and the non-opening area BK2 in which the auxiliary wiring is disposed in comparison with the section SP of the same sub-pixel, it can be confirmed that BK1 is larger than BK2. This is due to the space due to the size of the barrier rib 490 in the structure of FIG. 4 in which the barrier rib 490 is erected again after the bank is etched to form the barrier rib, and the auxiliary electrode 441 between the barrier rib 490 and the bank 450 . ) is required, so the section of BK1 is increased. On the other hand, in the case of FIGS. 5 and 6 to which the present invention is applied, only the region BK2 sufficient to form the bank 450 between adjacent sub-pixels is required, and the auxiliary electrodes 510a and 510b can be disposed on the bank. , it is possible to increase the aperture ratio when the present invention is applied.

8 to 12 are views illustrating a process of laminating the structure of FIG. 5 according to an embodiment of the present invention.

8 is a cross-sectional view in which a thin film transistor, an anode 440 that is a first electrode connected thereto, and a bank 450 are disposed.

9 shows a form in which an auxiliary wiring material 510 and a photoresist 515 are applied to the entire surface of the bank 450 of FIG. 8 . The auxiliary wiring material 510 may use Mo, Cu, or an alloy of Mo and Cu, but is not limited thereto. In addition, the auxiliary wiring material 510 may use the same material as the material constituting the second electrode. The auxiliary wiring material 510 may be any type of material that can be electrically contacted with the second electrode, and is formed in the non-opening area, so it is not necessarily transparent, but is combined with a material for improving visibility or reducing the reflectance of external light. can be formed by

10A and 10B show cross-sections in which the photoresist 515 is exposed on the silver auxiliary wiring material 510 . FIG. 10A shows a cross-section when the photoresist uses negative photoresists 515a, 515b, and 515c, and FIG. 10B shows a case where the photoresist uses positive photoresists 515d, 515e, and 515f. shows a cross section of

11A and 11B show cross-sections in which auxiliary wirings 510a, 510b, and 510c are formed on the bank 450 . The auxiliary wiring material 510 may be etched in the photoresist 515 of FIG. 10 . 11A is an embodiment using the negative photoresist of FIG. 10A, and FIG. 11B is an embodiment using the positive photoresist of FIG. 10B.

The auxiliary wirings 510a, 510b, and 510c may be disposed on all the banks 450 of the display panel, or may be disposed only on some of the banks 450 according to another embodiment. This may be different in consideration of the aperture ratio, the influence of the voltage drop of the second electrode according to the size of the panel, and the like. In addition, the width of the bank in the region where the auxiliary wirings 510a, 510b, and 510c are disposed and the width of the bank in the region where the auxiliary wirings 510a, 510b, and 510c are not may be configured differently. When the width of the bank is increased, the width of the auxiliary wiring is also increased, thereby reducing the resistance of the second electrode to maintain uniform luminance. By applying this, the width of the bank in which the auxiliary wiring is located can be made wider than the width of the bank in which the auxiliary wiring is not located. Meanwhile, the size of the first electrode and the pixel area may be different for each pixel according to the emission color spectrum of the organic light emitting layer. In this case, since the width of the adjacent bank of the pixel area is wide and the auxiliary wiring is located, the total area and the aperture ratio of the auxiliary wiring can be increased because the opening ratio is not affected even when the bank is enlarged in the portion with the small pixel area. .

Thereafter, the organic light emitting layer 470 and the second electrode 480 may be formed. As shown in FIG. 11A , when the auxiliary wiring is formed using a negative photoresist, the cross section in which the organic light emitting layer 470 and the second electrode 480 are formed was previously described in FIG. 5 .

FIG. 12 shows a cross-section in which the organic light emitting layer 470 and the second electrode 480 are formed in the embodiment of FIG. 11B .

As shown in FIG. 6 , even when the first electrode 440 and the source/drain 420 of the thin film transistor are directly connected, the same structure of the bank may be applied. That is, the lamination process of FIGS. 8 to 12 may be applied.

The source or drain 420 of the thin film transistor may be directly connected to the first electrode 440 as shown in FIG. 6 . Meanwhile, the source or drain 420 of the thin film transistor may be connected to the connection electrode 430 in electrical contact with the first electrode 440 as shown in FIG. 5 . The present invention focuses on locating the auxiliary wiring on the bank, and is not limited to a specific configuration of the first electrode 440 or the thin film transistor.

13 to 15 are plan views illustrating a process in which auxiliary wirings are stacked in the same structure as in FIG. 6 . For convenience of explanation, the protective layer is not shown.

13 is a view showing a plane in which the elements 405 , 410 , 418 , and 420 constituting the thin film transistor, the first electrode 440 , and the bank 450 are formed.

14 is a view showing an auxiliary wiring material 510 coated on the entire surface of the display panel. 9 to 12 , after the photoresist is applied, the photoresist is patterned, and the auxiliary wiring material 510 is etched. The photoresist may be selectively removed or maintained. In FIG. 14 , the photoresist is not shown for convenience of explanation.

15 is a diagram illustrating an auxiliary wiring 510 etched by etching according to an embodiment of the present invention. As previously shown in FIG. 11 , the auxiliary wiring 510 is disposed on the bank 450 .

16 is a view showing the auxiliary wiring 510 disposed on the bank in the panel when the present invention is applied. The anode 440 is disposed in the pixel region, and the auxiliary wiring 510 is positioned between the pixel regions.

In addition, in FIG. 16 , power (base power) having the same potential as the cathode, which is the second electrode, such as 1650 or 1660, is applied to one or both ends of the auxiliary wiring 510, so that the base power on the display panel can be uniformly applied. let it be This makes the luminance of the edge area and the center area of the display panel uniform. Power having the same potential as the cathode, which is the second electrode, may be applied to both left and right sides in the 1650 direction or may be applied to either left or right side. In addition, power having the same potential as that of the cathode, which is the second electrode, may be applied to both upper and lower sides in the 1660 direction, or to either one of the upper and lower sides.

In FIG. 16 , auxiliary wirings 1810 and 1820 may be positioned between all pixel areas, but these may be variously configured in consideration of the aperture ratio.

In FIG. 17 , unlike FIG. 16 , the auxiliary wiring 510 is formed only in a part of the non-opening area between the pixel areas. This can be variously applied in consideration of the size and aperture ratio of the display panel. That is, not all of the non-opening areas between the pixel areas become the contact areas, but only some of the non-opening areas become the contact areas, so that the auxiliary wiring 510 is formed. As described above, since the width of the bank in which the auxiliary wiring is located can be widened and the width of the bank where the auxiliary wiring is not located can be narrowed, the area and the opening ratio of the entire auxiliary wiring can be adjusted.

18 is a view comparing the aperture ratio due to the arrangement of auxiliary wirings and the aperture ratio due to the arrangement of auxiliary wirings in the partition structure of FIG. 4 . 1810 is a simplified structure of the partition wall of FIG. 4 , Width_Wall indicates the width of the partition wall 490 , Width_bk indicates the width of a bank disposed below the partition wall, and Width_auc indicates the width of the auxiliary electrode 441 . 1820 shows an example in which auxiliary wiring is arranged when the present invention is applied as shown in FIGS. 5 and 6 .

For convenience of comparison, the length over which the bank 450 covers the first electrode 440 and the length over which the bank 450 covers the auxiliary wiring 441 of FIG. 4 are indicated by Dist(b, e), and the bank ( The minimum distance maintained between the 450 and the bank 450 is referred to as Dist(b, b). And the minimum distance required between the electrodes or wirings is called Dist(e, e).

18 to 1810, the portion corresponding to the non-opening area is w1, which is calculated by Equation 1 below.

[Equation 1]

w1 = 2*Dist(e, e) + 2*Dist(b, e) + wdth_auc =

2*Dist(e, e) + 2*Dist(b, e) + 2*Dist(b, e) + 2*Dist(b, b) + width_bk =

2*Dist(e, e) + 4*Dist(b, e) + 2*Dist(b, b) + width_bk

Meanwhile, in 1820, the portion corresponding to the non-opening area is w2, which is calculated by Equation 2 below.

[Equation 2]

w2= Dist(e, e) + 2*Dist(b, e)

Comparing Equation 1 and Equation 2, the difference between w2 and w1 is the same as Equation 3.

[Equation 3]

w1-w2= Dist(e, e) + 2*Dist(b, e) + 2*Dist(b, b) + width_bk

If the value of Dist(b, b) is 21.5um, the value of Dist(b, e) is 5um, the value of Dist(e, e) is 8um, and the value of width_bk is 5um, Fig. 4 is applied w1 is 84 um, and w2 of the embodiment to which FIG. 5 is applied is 18 um. That is, w1-w2 becomes 66 um, so it can be seen that the present invention increases the aperture ratio.

When the present invention is applied, the opening area increases by the value of Equation (3). This is because the problem of making separate banks to form the partition wall 490 is eliminated in the present invention.

19 is a view showing an increase in the luminance lifetime of a panel according to an increase in the aperture ratio due to the application of the present invention. When the aperture ratio of the panel increases by 13.5% from 30% to 43.5%, the luminance lifetime increases from 45000 hours to 58000 hours for 150/450 nits by about 13000 hours, and for 150/500 nits, the luminance lifetime increases from 42000 hours to 54000 hours shows an increase of about 12000 hours.

When the present invention is applied, since the auxiliary wiring is disposed on the bank, the possibility of contact with the first electrode is reduced. To this end, the thickness of the bank may be greater than that of the organic light emitting layer and the cathode, which is the second electrode.

Comparing the configuration of FIGS. 5 and 6 with the configuration of FIG. 4 , the process efficiency can be increased by applying the mask No. 4 according to the generation of the barrier rib. That is, 6 masks are applied when creating the barrier rib in FIG. 4 , but in the case of FIGS. 5 and 6 , the PAC 427 , the anode 440 , the bank 450 , and the auxiliary wiring 510 and the photoresist 515 . A total of 4 masks are used using one mask. As a result, the number of masks can be reduced and process efficiency and cost savings can be increased.

In particular, when applied to the top light emission method, the same number of processes as that of the bottom light emission can be applied, thereby reducing the cost. In addition, since the barrier rib of FIG. 4 is removed and auxiliary wiring is placed on the bank, the display panel can be made thinner, and auxiliary wiring is formed in the contact area, which is a non-opening area between pixel areas, to solve the voltage drop problem of the cathode. The luminance can be made uniform. Also, as shown in FIGS. 18 and 19 , when the present invention is applied, as shown in 1820 , the opening ratio is the same as when only the banks are formed, and it can be seen that the opening ratio is significantly increased compared to the case 1810 when the partition wall is applied.

In the present invention, auxiliary wirings connected to the cathode may be arranged in a mesh form or a grid form on the bank. Alternatively, it may be arranged in parallel up and down or parallel to the left and right. The auxiliary wiring does not necessarily have to be disposed on all the banks, and may be disposed in a region where a voltage drop increases, for example, at the center of the display panel. The position where the auxiliary wiring is to be arranged on the bank may be variously applied depending on the embodiment, but the present invention is not limited thereto.

As shown in FIG. 16 , by applying the base power to the auxiliary wirings like the cathode, the base power can be uniformly applied even to the middle region of the display panel compared to the edge region of the display panel, so that the luminance is uniform in the display panel. can elevate the

20 is a view showing a process of manufacturing an organic light emitting display device according to an embodiment of the present invention.

First, a substrate is prepared and a thin film transistor is formed on the substrate (S2010). Then, a first electrode electrically directly or indirectly connected to the source or drain of the thin film transistor is formed (S2020). Here, the first electrode is formed in a plurality of pixel areas and is formed to be separated from other first electrodes in adjacent pixel areas. Then, a bank defining a pixel area is formed (S2030). An auxiliary wiring is formed on the bank (S2040). Looking at the formation of the auxiliary wiring in more detail, as previously shown in FIGS. 9 to 12, the auxiliary wiring is applied (coated) to the entire surface of the substrate, and photoresist is applied to the entire surface of the auxiliary wiring, and then the photoresist is masked. After exposure by using the method, the auxiliary wiring may be etched.

After forming the auxiliary wiring, the organic light emitting layer and the second electrode are formed (S2050). Here, the second electrode is formed on the organic light emitting layer to be electrically connected to the auxiliary wiring. In addition, the photoresist may be removed after the organic light emitting layer and the second electrode are formed.

21 is a view showing a cross-section in which the photoresist on the auxiliary wiring is removed according to an embodiment of the present invention. In the configuration of FIG. 5 , the photoresists 515a , 515b , and 515c and the organic light emitting material and the second electrode material applied thereon are removed.

22A and 22B are views illustrating a cross-section of an auxiliary wiring according to another embodiment of the present invention in a double layer. A structure in which the contact surface with the second electrode is widened by forming two materials having different etching degrees is presented. In FIG. 22A, the auxiliary wiring layer is a double layer such as 2200a, 2200b, 2200c, and 510a, 510b, 510c, and the first layer 2200a, 2200b, 2200c is less etched to have a larger area than 510a, 510b, 510c, and the second electrode ( 480) and it can be seen that the two auxiliary wiring layers are electrically in contact with each other. Conversely, in FIG. 22B , it can be seen that the lower first layers 2200a, 2200b, and 2200c are etched more, have a smaller area than 510a, 510b, and 510c, and are in electrical contact with both the second electrode 480 and the two auxiliary wiring layers. can When two or more materials having different etch rates are stacked for the auxiliary wiring, the contact surface between the auxiliary wiring and the second electrode is widened, so that the voltage drop of the second electrode can be prevented.

The above description and the accompanying drawings are merely illustrative of the technical idea of the present invention, and those of ordinary skill in the art to which the present invention pertains can combine configurations within a range that does not depart from the essential characteristics of the present invention. , various modifications and variations such as separation, substitution and alteration will be possible. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical spirit of the present invention, but to explain, and the scope of the technical spirit of the present invention is not limited by these embodiments. The protection scope of the present invention should be construed by the following claims, and all technical ideas within the equivalent range should be construed as being included in the scope of the present invention.

100: display device 110: display panel
120: first driving unit 130: second driving unit
140: timing controller 405: active
407: gate insulating film 410: gate
415: interlayer insulating film 420: source and drain
425: passivation layer 427, 435: planarization layer
430: connection electrode 440: first electrode
450: bank 470: organic light emitting layer
480: second electrode 510: auxiliary wiring
515: photoresist

Claims (11)

a substrate having a plurality of pixel regions defined thereon;
a first electrode positioned in each of the pixel regions;
a bank defining the pixel area;
auxiliary wiring on the bank;
an organic light emitting layer on the first electrode; and
a second electrode positioned on the organic light emitting layer and electrically connected to the auxiliary wiring;
The organic light emitting layer is positioned on the first electrode between the adjacent banks and is formed shorter than the first electrode,
The auxiliary wiring has an inclination angle having an obtuse angle on the contact surface in contact with the bank and is in electrical contact with the second electrode on the contact surface,
The auxiliary wiring has a two-layer structure in which a first layer and a second layer made of a material having at least two different etching degrees are stacked, and the second layer is disposed on the first layer,
The area of the side facing the second layer of the first layer is smaller than the area of the side facing the first layer of the second layer,
The second electrode is in contact with each of the first layer and the second layer.
delete delete According to claim 1,
An organic light emitting display device in which a photoresist, a material constituting the organic light emitting layer, and a material constituting the second electrode are stacked on the auxiliary wiring.
According to claim 1,
The auxiliary wiring is located only in a part of the banks.
6. The method of claim 5,
A width of a bank in which the auxiliary wiring is located is wider than a width of a bank in which the auxiliary wiring is not located.
According to claim 1,
An organic light emitting display device to which power having the same potential as that of the second electrode is applied to one end or the other end of the auxiliary wiring.
delete forming a first electrode in a plurality of pixel regions on a substrate;
forming a bank defining the pixel area;
forming an auxiliary wiring on the bank;
forming an organic light emitting layer on the substrate on which the auxiliary wiring is formed; and
Comprising the step of forming a second electrode electrically connected to the auxiliary wiring on the organic light emitting layer,
The step of forming the auxiliary wiring is
applying the auxiliary wiring to the entire surface of the substrate;
applying a photoresist on the auxiliary wiring;
exposing using the photoresist as a mask; and
etching the auxiliary wiring;
After the step of forming the second electrode
and removing the photoresist.

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